1. Field
The subject matter disclosed herein relates to providing a mobile station with assistance information related to estimating a position for the mobile station.
2. Information
The position of a mobile station, such as a cellular telephone, may be estimated based on information gathered from various systems. One such system may comprise a Global Navigation Satellite System (GNSS), which is one example of a satellite positioning system (SPS). SPS systems such as GNSS may comprise a number of space vehicles (SV) orbiting the earth. Another example of a system that may provide a basis for estimating the position of a mobile station is a cellular communication system comprising a number of terrestrial base stations to support communications for a number of mobile stations. A further example of a system that may provide a basis for estimating the position of a mobile station is a wireless network compatible with the Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless local access network (WLAN) standard, which may also be referred to as a Wi-Fi network. Such a network may include access points and sensors, for example.
A position estimate, which may also be referred to as a position “fix”, for a mobile station may be obtained based at least in part on distances or ranges measured from the mobile station to one or more transmitters, and also based at least in part on knowledge of the locations of the one or more transmitters. Such transmitters may comprise SVs in the case of an SPS and/or terrestrial base stations in the case of a cellular communications system and/or Wi-Fi/802.11x transmitters or similar beacon transmitters, for example.
An almanac may be maintained for systems used for position estimation. The almanac may contain various types of information, including, for example, information that may be used in position estimation operations. Such information may include the identities and locations of the various transmitters of the system, for example.